1. Field of the Invention
The present invention relates to a fluorescent tube connector device, a light source device having the fluorescent tube connector device, and a display having the light source device.
2. Description of the Related Art
In flat-type displays called “flat panel displays (FPD)” such as liquid crystal displays, a light source device for general illumination and a light modulating element (for example, a liquid crystal element in a liquid crystal display) are provided, and a predetermined light output can be made by a combination of the light source device and the light modulating element.
A variety of investigations have been made as to the configuration and kind of the light source device. In recent years, utilization of a fluorescent tube has been being deemed as promising, from the viewpoints of luminous efficiency, color gamut, long-term reliability, and the like.
Particularly, the hot cathode type fluorescent tube has been paid attention to because of its high luminous efficiency and high luminance. In a hot cathode type fluorescent tube, electrodes are provided at both end parts of a glass tube, a gas (such as argon gas) and mercury are sealed in the space inside the glass tube, and the internal surface of the glass tube is coated with a fluorescent material.
Meanwhile, in the case where fluorescent tubes including cold cathode tubes are incorporated into light source devices or the like, it may generally be necessary to electrically connect electrode pins at an end part or parts of the fluorescent tube to a peripheral apparatus. This connection has been made by a technique shown in FIG. 7 in which a wire extending from the peripheral apparatus is wound around the electrode pin of the fluorescent tube, and, after this operation or the like operation, the wire wound around the electrode pin is fixed by soldering.
It has been pointed out, however, that the connection part formed by this technique involves the problem of a kinetic load tending to be exerted on the wire, possibly resulting in an inconvenience in electrical characteristics due to wearout or breaking of the wire. In addition, the connection part formed by this technique would be larger than necessary, due to the wound wire and the solder.
On the other hand, there has been proposed a technique in which an electrode pin and a wire are inserted into and fixed in a connector, followed by calking, soldering or the like operation to thereby connect the electrode pin and the wire to each other (refer to, for example, Japanese Patent Laid-open No. Hei 9-259749).
With this technique, however, it is difficult to cope with another problem which is generated, particularly, in a hot cathode tube.
As shown in FIG. 8, a hot cathode tube has a structure in which two electrode pins are projecting in parallel at one end part of a fluorescent tube. In an extremely small diameter hot cathode tube constituting an FPD, the spacing between the two electrode pins is particularly small. Therefore, an attempt to fix the electrode pins by soldering may result in that the solder portions applied individually to the electrode pins make contact with each other, causing unnecessary electrical connection between the electrode pins.
For example, where the spacing between the electrode pins is only 0.7 mm on a center-to-center basis, the actual gap between the electrode pins obtained by subtracting the radii of the electrode pins is 0.4 mm, so that shortcircuit may not be obviated when the width of the wire is greater than 0.4 mm. In addition, even where the width of the wire is small, in order to obviate the electrical contact between the closely disposed electrode pins in the manufacturing process, it has been needed to adopt a method which is intricate to carry out manually and is low in assuredness, such as a method in which soldering for one of the electrode pins disposed side by side is conducted while covering the other.